| 摘要 |
<p>A ball-point pen capable of preventing backflow which is liable to occur during writing with the ball-point upward. The ball-point pen (1) comprises a tip (15), of which an end protrudes from a cap (7) with a ball-point pen refill (3) rotatably holding at the front end thereof a small ball (13) for writing by caulking, an ink storage tube (17), in which ink is filled for supplying of ink to the tip, and a joint (19) which connects the ink storage tube to the tip to permit ink to be fed from the ink storage tube to the tip. Formed on the joint are a tip side hole (37a) and an ink storage tube side hole (33a) which permit ink to pass therethrough when the joint is fitted into the tip and the ink storage tube, respectively. The tip side hole and the ink storage tube side hole communicate to each other through a connection hole (45) which comprises a large diameter portion (45b) and a small diameter portion (45s) adapted to connect to the tip side hole and the ink storage tube side hole, respectively, and is eccentric with respect to the both holes. A large ball (49) having a larger diameter (1s) of the small diameter portion is movably disposed in at least a portion (47) of a space which is formed between a rear end of the tip and the large diameter portion when the tip is fitted in the tip side hole.</p> |
